Paleomagnetic results from lower Triassic red sandstones from the autochthonous cover of the Central Western Carpathians: constraints on largescale rotations of the Alcapa microplate.

Paper Number: 3790

Paleomagnetic results from lower Triassic red sandstones from the

autochthonous cover of the Central Western Carpathians: constraints on

large-scale rotations of the Alcapa microplate.

Szaniawski R. 1_{, Jankowski L.} 2_{, Ludwiniak M.} 3_{, Mazzoli S.}4

1 _{Institute of Geophysics, PAS, Ks. Janusza 64, 01-452 Warszawa, Poland, rafsz@igf.edu.pl} 2 _{Geological Institute, Carpathian Branch, Skrzatów 1, 31-560 Kraków, Poland}

3 _{Institute of Geology, University of Warsaw, Żwirki i Wigury 93, 02-089 Warszawa, Poland}

4 _{Department of Earth Sciences, University of Naples “Federico II”, Largo S. Marcellino, 10, 80138 Naples, Italy}

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The Carpathian orogen formed as a result of collision of the Alcapa and Tisza-Dacia microplates with the European Platform. With the objective of better constraining the regional paloegeographic evolution, we carried out paleomagnetic studies within the Central Western Carpathians, which constitutes a fragment of the Alcapa microplate. This study is a continuation of our earlier works performed in the Tatra Mts where we studied lower Triassic red sandstones from the autochthonous cover of the crystalline basement. This time we investigated rocks of matching age, lithology and tectonic position, from the area of two nearby mountain massifs: Low Tatra and Velka Fatra.

Petromagnetic analyses provided similar results for all the studied sites. Red sandstones are rich in hematite and contain only small amounts of low coercivity ferromagnetic minerals. Hematite carrier records one characteristic component characterized by maximum unblocking temperatures of 680°C. This component displays dominantly normal polarity with shallow to moderate inclinations and north directed declinations (after the tectonic correction).

The results obtained in this study are incompatible with previous paleomagnetic studies pointing to large-scale counterclockwise rotations of the Alcapa. On the other hand, our new findings are in good agreement with our previous results from the Tatra Mts. Observed inclinations are similar to that expected from reference paleomagnetic data from the European Platform, whereas declination values indicate only moderate counterclockwise rotations of about 20°.

Acknowledgements: this work was supported by Polish National Science Centre (NCN) (Grant nr. 2014/13/B/ST10/01151).